function foo (a : number, b ? : number, c ? : number) : boolean {
    return foo1 (a, b, c);
}
function foo1 (a : number, b ? : number, c ? : number) : boolean {
    return a == Number (b) == Boolean (c);
}
export default function isEqual (a : any) : boolean {
    return foo (a);
}
console.log (foo (1, 2, 3));
